Heat pump thoughts

[Nonhog]

3 bids for heat pumps. 3 different suggestions.

A little background. 1700 sq. ft. home with a 15x15 unconditioned atrium in the center. The entire roof is glass and the back wall is near 18' tall.
(lots of volume)

Currently we have propane furnace and water heater.

Our goals are lower utility costs. Stop burning wood. (I know 2 directions right there)
Make the atrium warmer in winter and cooler in summer.(not perfect-just better)
Probably by adding registers to the atrium walls.

Back to the bids.
1st company suggests adding a ductless wall mount in the atrium. and opening the windows to the main room(s) allowing heat to filter.
(I'm no expert but that co. will not get the job)

2nd company, suggest adding 3 ton heat pump to current Propane furnace.
Sounds logical to me.

3rd company says get rid of propane furnace as well as our instant hot water heater (also propane)and add there 4 ton system.
He didn't suggest a new water heater so I can only assume he means get an electric instant water heater which is off topic. Deal with that later.

I always thought electric heat pumps don't perform well in very cold weather.
Seattle area gets a few days a year below 30.
My co-worker has a electric heat pump and said its fine in the winter.

Our propane furnace is only a few years old. Should I retain it as a hybrid
system for our home or move it to my shop?
Not giving it to anyone to recycle.(as suggested)

Thoughts?
More info needed? If so what?
Thanks!